Vaginal delivery involves a high risk of pelvic injury damage that can lead to lifelong pelvic floor disorders for mothers, and can be a stressful event for babies where long delivery times, instrumented deliveries, and C- sections are the result of difficult deliveries. Both maternal injuries and longer delivery times are challenged that are posed by the same biomechanical phenomenon of pelvic tissue resistance during childbirth. Currently, there are no dilation protocols or devices that can shorten delivery and prevent pelvic tissue injuries. There is an urgent unmet clinical need to ease delivery and prevent injuries that may arise from childbirth. The Materna Device is a mechanical birth dilator that pre-stretches pelvic muscles over ~1 hour during the first phase of labor, thus easing delivery by reducing tissue resistance. It was used safely as designed during the second active phase of labor in 38 subjects. No injuries, lacerations, vaginal tearing, or adverse events occurred due to its usage. In this SBIR Fast-Track application, we plan to (i) optimize dilation protocol as to time and duration of placement of the Device; (ii) reduce delivery time by 20%; and (iii) lower the risk of pelvic tissue injury from 33% of all births to less than 20%. This Project is based on a proven collaboration between Materna Medical (device functionality and safety features), Baylor College of Medicine (clinical study and data) and the Pelvic Floor Research Group at the University of Michigan (modeling of tissue biomechanics). Our Specific Aims are to: 1) Determine the optimal clinical protocol for the Materna Device using computer simulations. Computer models will be updated to optimize the dilation protocol for the Device using biomechanical data from the prior clinical Phase I study. 2) Finalize Materna Device design; build and produce Devices for the study. The Phase II study Device design is essentially complete; here we will bench test the design, and update its data collection system. 3) Submit and receive approval of Clinical Protocol. Once the required Device modifications that provide the optimal dilation protocol have been determined, the Clinical Protocol will be finalized and submitted for IRB approval. 4) Demonstrate in a randomized controlled trial conducted at a single site (n=100), that pre-dilation by the Materna Device of the vaginal canal and pelvic floor muscles to 8 cm during the first stage of labor could shorten the second stage of labor and lead to fewer pubovisceral muscle tears and avulsions. This Phase II study is designed to provide the data required to submit the Materna Device for FDA clearance. 5) Utilize computer simulations to develop predictive parameters to identify women at-risk for sequelae following vaginal delivery. Here, we will use patient data from Aim 4 to update our biomechanical model so it will better predict birth canal behavior during delivery. If successful, we believe the Materna Device may become part of a new standard of care for childbirth, which could lower instrumented deliveries and emergency C-section rates, as well as reduce pelvic muscle injuries and lifelong pelvic floor disorders for immediate improvements in care and reductions in long-term sequelae.